Heat Exchanger requires minimal

HEAT EXCHANGER REQUIRES MINIMAL

Heat Exchanger requires minimal pre-ventive maintenance compared to chillers and pumps, however maintenance is still a necessity to ensure proper operation. Back flushing the plate heat exchanger once a week is one PM step to an optimally running unit.

the PHE and cleaning it during a planned 5–10-hour shutdown.PM guidelines Follow these preventive measures to avoid unexpected down-time, failures and high operating costs:
1. Ironically, the plate heat exchanger can become one of the best flters in a system. If it is connected to an open loop without a fltration system (such as open cooling-tower water, river water or seawater), the narrow gaps between the plates of the heat exchanger will trap all kinds of debris and materi-als—including silt, sand, rocks, leaves and shells. Over time, the sub-micron particles can build up on the plates, result-ing in decreased thermal performance and increased pressure drop. Make sure the system has adequate fltration to keep the fuids clean and prevent clogging. Some manufacturers can help with custom flter solutions developed just for their plate heat exchanger units.
2. Regularly back fush the system or heat exchanger every week to push debris back to the source. Some manufacturers can provide back-fush valves.
3. Regularly check the plate heat exchanger for leaks, es-pecially during intense running periods. Simply remove the protective shroud and visually inspect the side and particular-ly the bottom of the plate pack with a fash light.
4. Plan your downtime to take the heat exchanger offine and perform a mechanical cleaning every one to three years, depending on the condition of the process waters. If the wa-ter is clean and regular back fushing of the system is per-formed, the unit may not need to be taken offine for up to 10 years.
5. Check the gaskets as often as possible to look for soft-ness and elasticity, as brittle gaskets are not good.
6. Install a water-cleaning system. Be mindful of the chlo-rination volume. A good cleaning system will soften the wa-ter and prevent hard scaling and fouling from coating the plates, but too much chlorine will affect the stainless-steel plates and can possibly cause corrosion.In brief:
Back fush the plate heat exchanger once a week; Perform a mechanical cleaning every two to three years if the water is dirty and every fve to 10 years if the water is clean.Change gaskets every fve to 10 years (depending on the application, temperatures and fuids); and Send the plates back to the factory for a reconditioning process every 10–15 years (not all manufacturers offer this service).

Marco Terenghi is a Parts and Service Specialist with Alfa Laval. His expertise is centered on heat exchangers and heat-transfer mechanical and hydraulic-working principles. For more informa-
tion, e-mail: [email protected] or visit